net/mlx5: LAG, check if all eswitches are paired for shared FDB

Shared FDB LAG can only work if all eswitches are paired.
Also, whenever two eswitches are paired, devcom is marked as ready.

Therefore, in case of device with two eswitches, checking devcom was
sufficient. However, this is not correct for device with more than
two eswitches, which will be introduced in downstream patch.
Hence, check all eswitches are paired explicitly.
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/eswitch.h

@@ -779,6 +779,13 @@ static inline int mlx5_eswitch_num_vfs(struct mlx5_eswitch *esw)
 	return 0;
 }
 
+static inline int mlx5_eswitch_get_npeers(struct mlx5_eswitch *esw)
+{
+	if (mlx5_esw_allowed(esw))
+		return esw->num_peers;
+	return 0;
+}
+
 static inline struct mlx5_flow_table *
 mlx5_eswitch_get_slow_fdb(struct mlx5_eswitch *esw)
 {
@@ -826,6 +833,8 @@ static inline void
 mlx5_eswitch_offloads_single_fdb_del_one(struct mlx5_eswitch *master_esw,
 					 struct mlx5_eswitch *slave_esw) {}
 
+static inline int mlx5_eswitch_get_npeers(struct mlx5_eswitch *esw) { return 0; }
+
 static inline int
 mlx5_eswitch_reload_reps(struct mlx5_eswitch *esw)
 {

drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c

@@ -828,7 +828,9 @@ bool mlx5_shared_fdb_supported(struct mlx5_lag *ldev)
 				      MLX5_DEVCOM_ESW_OFFLOADS) &&
 	    MLX5_CAP_GEN(dev1, lag_native_fdb_selection) &&
 	    MLX5_CAP_ESW(dev1, root_ft_on_other_esw) &&
-	    MLX5_CAP_ESW(dev0, esw_shared_ingress_acl))
+	    MLX5_CAP_ESW(dev0, esw_shared_ingress_acl) &&
+	    mlx5_eswitch_get_npeers(dev0->priv.eswitch) == MLX5_CAP_GEN(dev0, num_lag_ports) - 1 &&
+	    mlx5_eswitch_get_npeers(dev1->priv.eswitch) == MLX5_CAP_GEN(dev1, num_lag_ports) - 1)
 		return true;
 
 	return false;